Novell Doc: Identity Manager 3.5.1 Driver for Delimited Text: Implementation Guide

8.4 How Synchronization Works

After the Metadirectory engine determines that an object is to be synchronized, the following processes occur:

Each system (the Identity Vault and the connected system) is queried for all attribute values in the appropriate filters.
- eDirectory is queried for all values in the Subscriber filter, and for values that are marked for synchronization in Identity Manager 2.x and Identity Manager 3.x.
- The connected system is queried for all values in the Publisher filter, and for values that are marked for synchronization in Identity Manager 2.x and Identity Manager 3.x.
The returned attribute values are compared, and modification lists are prepared for the Identity Vault and the connected system according to Table 8-1, Table 8-2, and Table 8-3.

In the tables the following pseudo-equations are used:
- “Left = Right” indicates that the left side receives all values from the right side.
- “Left = Right[1]” indicates that the left side receives one value from the right side. If there is more than one value, it is indeterminate.
- “Left += Right” indicates that the left side adds the right side values to the left side’s existing values.
- “Left = Left + Right” indicates that the left sides receives the union of the values of the left and right sides.

Identity Manager has three different combinations of selected items in the filter, and each one creates a different output.

8.4.1 Scenario One

The attribute is set to Synchronize on the Publisher and Subscriber channels, and the merge authority is set to Default.

Figure 8-1 Scenario One

Table 8-1 contains the values that the Metadirectory engine synchronizes when the attribute is sent through a filter that is set to the configuration for Scenario One. The table shows different outputs depending upon the following:

Whether the attribute comes from the Identity Vault or the Application
If the attribute is single-valued or multi-valued, and if the attribute is empty or non-empty
If the attribute is empty or non-empty

Table 8-1 Output of Scenario One

	Identity Vault single-valued empty	Identity Vault single-valued non-empty	Identity Vault multi-valued empty	Identity Vault multi-valued non-empty
Application single-valued empty	No change	App = Identity Vault	No change	App = Identity Vault[1]
Application single-valued non-empty	Identity Vault = App	App = Identity Vault	Identity Vault = App	Identity Vault + = App
Application multi-valued empty	No change	App = Identity Vault	No change	App = Identity Vault
Application multi-valued non-empty	Identity Vault = App[1]	App + = Identity Vault	Identity Vault = App	App = App + Identity Vault Identity Vault = App + Identity Vault

8.4.2 Scenario Two

The attribute is set to Synchronize only on the Subscriber channel, or it is set to Synchronize on both the Subscriber and Publisher channels. The merge authority is set to Identity Vault.

Figure 8-2 Scenario Two

Table 8-2 contains the values that the Metadirectory engine synchronizes when the attribute is sent through a filter that is set to the configuration for Scenario Two. The table shows different outputs depending upon the following:

Whether the attribute comes from the Identity Vault or the Application
If the attribute is single-valued or multi-valued
If the attribute is empty or non-empty

Table 8-2 Output of Scenario Two

	Identity Vault single-valued empty	Identity Vault single-valued non-empty	Identity Vault multi-valued empty	Identity Vault multi-valued non-empty
Application single-valued empty	No change	App = Identity Vault	No change	App = Identity Vault[1]
Application single-valued empty	App = empty	App = Identity Vault	Identity Vault = App	App = Identity Vault[1]
Application multi-valued empty	No change	App = Identity Vault	No change	App = Identity Vault
Application multi-valued non-empty	App = empty	App = Identity Vault	App = empty	App = Identity Vault

8.4.3 Scenario Three

The attribute is set to Synchronize on the Publisher channel, or the merge authority is set to Application.

Figure 8-3 Scenario Three

Table 8-3 contains the values that the Metadirectory engine synchronizes when the attribute is sent through a filter that is set to the configuration for Scenario Three. The table shows different outputs depending upon the following:

Whether the attribute comes from the Identity Vault or the Application
If the attribute is single-valued or multi-valued
If the attribute is empty or non-empty

Table 8-3 Output of Scenario Three

	Identity Vault single-valued empty	Identity Vault single-valued non-empty	Identity Vault multi-valued empty	Identity Vault multi-valued non-empty
Application single-valued empty	No change	Identity Vault = empty	No change	Identity Vault = empty
Application single-valued non-empty	Identity Vault = App	Identity Vault = App	Identity Vault = App	Identity Vault = App
Application multi-valued empty	No change	Identity Vault = empty	No change	Identity Vault = empty
Application multi-valued non-empty	Identity Vault = App[1]	Identity Vault = App[1]	Identity Vault = App	Identity Vault = App